Central Bureau for Astronomical Telegrams
IAUC 7893: XTE J0929-314; 2002ck
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Circular No. 7893
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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XTE J0929-314
R. A. Remillard, Massachusetts Institute of Technology; and J.
Swank and T. Strohmayer, Goddard Space Flight Center, NASA, report
the discovery of 185-Hz pulsations in XTE J0929-314 (IAUC 7889).
This source was observed in a brief pointed observation with RXTE
on May 2, while the average flux was 28 mCrab (2-30 keV). A power
spectrum was computed for 800 s of PCA data, and a highly
significant pulsation is seen at 185.09 Hz, with a strong harmonic
at 370.18 Hz. This is the third known pulsar in which pulsations
faster than 10 ms can be seen in the persistent x-ray emission.
Rasters across the source give an improved position R.A. =
9h29m18s, Decl. = -31o23'.1 (equinox J2000.0; systematic
uncertainty 1'), consistent with the optical candidate (IAUC 7889).
M. P. Rupen, V. Dhawan, and A. J. Mioduszewski, National Radio
Astronomy Observatory, report the detection of a radio counterpart
to the x-ray transient XTE J0929-314 (IAUC 7888). Observations
with the Very Large Array (VLA) at 4.86 GHz show a source with flux
density 0.31 +/- 0.07 mJy on May 3, and 0.36 +/- 0.05 mJy on May 7,
at R.A. = 9h29m20s.194, Decl. = -31o23'03".41 (equinox J2000.0;
uncertainty +/- 0".3). This is 0".8 from the optical position
reported by Greenhill et al. (IAUC 7889) and provides strong
evidence that this optical identification is correct. Further
optical and x-ray observations are strongly encouraged.
P. Cacella, Brasilia, Brazil, reports that an unfiltered CCD
image taken with a 0.25-m reflector shows a variable (mag 18.3)
that is possibly the optical counterpart to XTE J0929-314 at
position end figures 20s.22, 03".6.
SUPERNOVA 2002ck IN UGC 10030
T. Matheson, S. Jha, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
2002ck (cf. IAUC 7884), obtained by M. Calkins on May 2.45 UT with
the F. L. Whipple Observatory 1.5-m telescope (+ FAST spectrograph),
shows it to be a type-Ia supernova near maximum. Adopting the
NASA/IPAC Extragalactic Database recession velocity of 8953 km/s
for the host galaxy, the supernova expansion velocity is about
10400 km/s for Si II (rest 635.5 nm) and 14400 km/s for Ca II (rest
395.1 nm). The spectral-feature age of the supernova (cf. IAUC
7774) is 1 +/- 2 days before maximum light.
(C) Copyright 2002 CBAT
2002 May 7 (7893) Daniel W. E. Green
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